Fertilization is done by germination of pollen on the pistil, without need of moisture as in the case of ferns (character they share with other Spermaphytes).
In Angiosperms fertilization has three essential characteristics:
* it is siphonogamous: the apertured pollen grain possessing two or three cells sees its vegetative cell germinate and form a pollen tube which will convey, with the help of its cytoskeleton, the male gamete (case of the tricellular pollen) where the generating cell ( case of the bicellular pollen) which will carry out its second division of meiosis. In this siphonogamy corresponds to a total franking of water for fertilization.
* it is anisogamous: the female gamete is by far the most massive of the two (the pollen grain is often very dehydrated, the cells it contains have a very small cytoplasmic space).
* it is double: the male gametes conveyed by the pollen grain will merge their nuclei (caryomixis) with those of two different cells. It's a special function for the reproduction of angiosperms. The pollen grain contains two nuclei (all haploids), whereas for example the mammalian spermatozoa contains only one.
Answer: The surgical removal of male reproductive organs is known as Orchidectomy.
Explanation: By the process of Orchidectomy male reproductive organs ( one or both the testes ) removed surgically. Orchidectomy is also known as Castration.
Orchidectomy is very helpful in case of testicular cancer. Because in that case it serve as treatment of cancer.
Orchidectomy is of three types -:
1 : Simple -: In this type of orchidectomy male gonads and spermatic cord is removed by incision. For the treatment genetic infection.
2 : Subcapsular -: In this type of orchidectomy not the entire gland only glandular tissues are removed. It is a Prostrate cancer treatment.
3: Inguinal :- In this type one or both the testes or entire spermatic cord is removed in incision in lower abdomen.
Long line fishing, drift nets, and trawling all produce an insignificant amount of by-catch is a false statement.
Explanation:
Bycatch fishing is "the incidental capture of non-target species” like sharks, dolphins, seabirds, marine turtles and other marine organisms while applying modern fishing gears like long line fishing, drift nets, or trawling.
Although, these inconspicuous modern fishing gears are highly efficient in catching the desired types of target fishes; these also catch significant amount of other marine species which travel along the line as a bycatch.
A huge number of exclusive marine fishes which are mostly under the endangered list and many juvenile fishes are caught as bycatch which are mostly thrown back dead overboard. Further these modern gears also endanger the marine structures like the coral reefs.
Micro-organisms can spread to person to person
Answer:
poor conductors
Explanation:
all metals conduct energy
